The present invention relates to a method of producing an optical integrated circuit in which a plurality of waveguide-type optical devices are integrated on a substrate, and more particularly to a method of producing an optical integrated circuit capable of optical wiring between the waveguide-type optical devices even after formation of the waveguide-type optical devices with different connection but a similar configuration.
In recent years, to cope with advent of our highly computerized society, the research, development, and practical use of optical fiber communication for transmitting information with a larger capacity have rapidly been promoted. Conventionally, the use of optical communication was essentially for communicating from one point to another pint, communication on a so-called point-to-point basis. Accordingly, only a single photodiode or a transmitter has satisfactorily been used as an optical device.
However, the following items will be significant problems in the near future, namely (1) in photonic switching techniques, light signals are processed without conversion into electrical signals, (2) in wavelength division multiplexing transmission, a plurality of rays emitted from a plurality of semiconductor laser sources are transmitted together through a single optical fiber, and (3) in coherent light transmission techniques, complicated processing of signals is required at the receiver end. In such a system necessitating complicated processing, combining each optical device with hybrid junctions with each other may not be considered as a satisfactory method from a cost and reliability standpoint. Thus, research and development have just started for a so-called optical integrated circuit in which the required optical devices are monolithically integrated on a substrate and in particular for an optical integrated circuit in which a plurality of different optical devices are integrated on the same substrate. A method of optical wiring for connecting between a plurality of optical devices has not yet been proposed.